# -*- coding: utf-8 -*-
# @Time : 2018/3/26 12:36 
# @Author : Lv Zhangrun 
# @Site :  
# @File : Calculate.py 
# @Software: PyCharm
import Stack
import Fraction


class Calculator:
    def __init__(self):
        self.numberStack = Stack.Stack()
        self.symbolStack = Stack.Stack()
        self.top = ""
        self.listOperators = ["+", "-", "×", "÷", "(", ")","="]

    def getFraction(self, strFraction, featureSymbol):
        listFraction = strFraction.split(featureSymbol)
        if featureSymbol=="/":
            return listFraction
        else:
            strTemp = listFraction[1]
            listTemp = strTemp.split("/")
            temp = []
            temp.append(int(listFraction[0]) * int(listTemp[1]) + int(listTemp[0]))
            temp.append(int(listTemp[1]))
            return temp

    def symbolLeftBracket(self, symbol):
        return True

    def symbolMultipleSign(self, symbol):
        if self.top == "+" or self.top == "-":
            return True
        else:
            return False

    def symbolDivisionSign(self, symbol):
        if self.top == "+" or self.top == "-":
            return True
        else:
            return False

    def symbolPlusSign(self, symbol):
        return False

    def symbolMinusSign(self, symbol):
        return False

    def symbolRightBracket(self, symbol):
        return False

    def symbolEqualSign(self, symbol):
        return False

    def comparePri(self, symbol):
        switch = {
            "(": self.symbolLeftBracket("("),
            "×": self.symbolMultipleSign("×"),
            "÷": self.symbolDivisionSign("÷"),
            "+": self.symbolPlusSign("+"),
            "-": self.symbolMinusSign("-"),
            ")": self.symbolRightBracket(")"),
            "=": self.symbolEqualSign("=")
        }
        if self.symbolStack.isEmpty():
            return True
        self.top = self.symbolStack.peek()
        if self.top == "(":
            return True
        if symbol not in switch.keys():
            return True
        else:
            return switch[symbol]

    def checkBrackets(self, expression):
        stack = Stack.Stack()
        b = False
        for i in expression:
            if i == "(":
                stack.push(i)
            if i == ")":
                if stack.isEmpty() or stack.pop() != "(":
                    return False
            if i == "=":
                if b:
                    return False
                b = True
        if stack.isEmpty() == False:
            return False
        if expression[len(expression) - 1:] != "=":
            return False
        return True

    def calculate(self, expression):
        expression.strip()  # 去空格
        if len(expression) > 1 and expression[len(expression) - 1:] != "=":
            expression = expression + "="
        if self.checkBrackets(expression) == False:
            print("错误：表达式有误！")
            return "0"
        listTemp = []
        for element in expression:
            if element not in self.listOperators:
                listTemp.append(element)
            else:
                strTemp = ""
                for i in listTemp:
                    strTemp = strTemp + str(i)
                if len(strTemp) != 0:
                    self.numberStack.push(strTemp)
                    listTemp.clear()
                while self.comparePri(element) == False and self.symbolStack.isEmpty() == False:
                    number1 = str(self.numberStack.pop())
                    number2 = str(self.numberStack.pop())
                    # print("number1:"+number1)
                    # print("number2:"+number2)
                    # fraction1 = None
                    # fraction2 = None
                    if "’" in number1:
                        temp1 = self.getFraction(number1, "’")
                        # print("temp1:"+str(temp1))
                        fraction1 = Fraction.Fraction(temp1[0], temp1[1])
                    elif "’" not in number1 and "/" in number1:
                        temp1 = self.getFraction(number1, "/")
                        # print("temp1:" + str(temp1))
                        fraction1 = Fraction.Fraction(temp1[0], temp1[1])
                    else:
                        fraction1 = Fraction.Fraction(int(number1), 1)
                    if "’" in number2:
                        temp2 = self.getFraction(number2, "’")
                        # print("temp2:" + str(temp2))
                        fraction2 = Fraction.Fraction(temp2[0], temp2[1])
                    elif "’" not in number2 and "/" in number2:
                        temp2 = self.getFraction(number2, "/")
                        # print("temp2:" + str(temp2))
                        fraction2 = Fraction.Fraction(temp2[0], temp2[1])
                    else:
                        fraction2 = Fraction.Fraction(int(number2), 1)
                    symbol = self.symbolStack.pop()
                    if symbol == "+":
                        self.numberStack.push(fraction2.plus(fraction1).getResult())
                    elif symbol == "-":
                        self.numberStack.push(fraction2.minus(fraction1).getResult())
                    elif symbol == "×":
                        self.numberStack.push(fraction2.multiply(fraction1).getResult())
                    elif symbol == "÷":
                        if fraction1.numerator == 0:
                            print("错误：不能出现除数为0的情况")
                            return None
                        else:
                            self.numberStack.push(fraction2.divide(fraction1).getResult())
                if element != "=":
                    self.symbolStack.push(element)
                    if element == ")":
                        self.symbolStack.pop()
                        self.symbolStack.pop()
        return self.numberStack.pop()